EP 0049241 B1 19841010 - METHOD AND APPARATUS FOR CONTROLLING AN AC INDUCTION MOTOR
Title (en)
METHOD AND APPARATUS FOR CONTROLLING AN AC INDUCTION MOTOR
Publication
Application
Priority
SE 8000118 A 19800108
Abstract (en)
[origin: WO8102076A1] A method and apparatus for controlling an AC induction motor, having at least two phases. The motor is controlled in a known manner by two input signals S1, S2, which are connected to a resolver (1), the output signals of which are used to generate separate supply signals to the motor phases. A measured signal U, representing the rotational speed of the motor, is fed lack to the control system and is used for calculating the oscillator frequency of the oscillator (5), which drives the resolver. A calculating circuit calculates the oscillator frequency as the sum of the first control signal S1 multiplied by a first constant factor, and the tachometer signal U multiplied by a second constant factor. As a result of this control method the oscillator frequency will increase with increasing control signal S1 and increasing tachometer signal U, but decrease with increasing motor load, because the motor speed will decrease. This automatic frequency adjustment results in constant amplitude of the stator magnetic field at all motor speeds and at all different loads.
IPC 1-7
IPC 8 full level
H02P 21/00 (2006.01); H02P 27/06 (2006.01); H02P 21/12 (2006.01); H02P 27/04 (2006.01)
CPC (source: EP US)
H02P 21/36 (2016.02 - EP US)
Designated contracting state (EPC)
AT CH DE FR GB LI LU NL
DOCDB simple family (publication)
WO 8102076 A1 19810723; BE 886987 A 19810707; CA 1164932 A 19840403; DE 3069436 D1 19841115; EP 0049241 A1 19820414; EP 0049241 B1 19841010; FI 66508 B 19840629; FI 66508 C 19841010; FI 820132 L 19820115; IT 1142253 B 19861008; IT 8147513 A0 19810106; JP H0250718 B2 19901105; JP S56501866 A 19811217; SE 420141 B 19810914; SE 8000118 L 19810709; SU 1435164 A3 19881030; US 4458193 A 19840703
DOCDB simple family (application)
EP 8000152 W 19801221; BE 203417 A 19810107; CA 367964 A 19810106; DE 3069436 T 19801221; EP 81900063 A 19801221; FI 820132 A 19820115; IT 4751381 A 19810106; JP 50026381 A 19801221; SE 8000118 A 19800108; SU 3388958 A 19820205; US 28775981 A 19810728